Image capture is the process of obtaining a digital image from a scene or a hard copy image such as an image printed on paper. This involves detecting light reflected from, or transmitted by or through the object of which the image is to be obtained.
In many situations, it is advantageous to increase the rate at which images can be obtained. This is the case, for example, with document scanners. However, as the throughput of a document scanner is increased, the available exposure time for each document decreases. This decrease in exposure time can result in increased image noise or the requirement for better quality optics which in turn increase the cost of manufacturing a document scanner.
US2007/0053022 discloses an image scanning apparatus that includes three color line sensors for outputting red, green, and blue color signals, a monochrome line sensor for outputting a monochrome signal having a higher resolution than the color signals, and a resolution enhancement processor. The resolution enhancement processor enhances a resolution of a pixel strength of the color signals, based on a monochrome smoothed value obtained by smoothing a signal of an arbitrary pixel of the monochrome signal and signals of pixels around the arbitrary pixel and a color smoothed value obtained by smoothing a signal of a pixel of each color signal and signals of pixels around the pixel of the color signal, the pixel of the color signal corresponding to the position of the arbitrary pixel of the monochrome signal.